The invention relates to a plastic part or fastener for engagement with a threaded bolt, especially a coarsely threaded bolt. The part includes an opening with several elastic catch points distributed about the circumference of the opening. The catch points in the zone of engagement with the threads of the bolt are provided with stepped graduations or tooth-like formations. Guide elements are arranged in the interspaces between the catch points distributed over the circumference of the opening.
Such a plastic part is already broadly known, as state of the art, in which the guide elements are designed as rigid stays or ribs situated in the interspaces between the catch points. See, for example, U.S. Pat. No. 4,728,236. The guide stays are, in the noted patent, above the catch points and have the function of guiding the threaded bolt over the whole height of the plastic part. However, if excessive tolerance variations occur in the threaded bolt, these guide stays can no longer perfectly fulfill their guiding function.
Also belonging to the state of the art is a known nut-type fastening element having four slots lying in opposed relationship and connected with each other by arcform stays. See for example, U.S. Pat. No. 4,77,582. In this known construction, however, no elastic catch points are provided over the circumference of the opening. Consequently, engagement with the threaded bolt takes place only through the arc form, and is thus relatively insecure.
Also belonging to the state of the art is an element for the elastic fastening of objects, in which, from the inner circumference of a sheath or socket form plastic element, ridges run obliquely toward the center. The ridges pass into a common wall provided with triangular guide stays on the inner circumference. See West German Disclosure 1,625,332. Here also, the holding effect is only slight, since, finally, the triangular guide stays can only be supported in a threaded bolt.